1. Field of the Invention
The present invention relates to a micro cross-section processing method, which may be used for observing a cross section of a semiconductor device, for example, and performs cross-section processing on a sample with a focused ion beam.
2. Description of the Related Art
Samples having minute patterns, such as a semiconductor device and a semiconductor laser device, are increasingly minute. Thus, those samples generally undergo cross-section processing with a focused ion beam (or FIB) for cross-section observation with an SEM. Recently, cross-section processing on a pattern of 100 nm or below has been required.
Accordingly, a technology (Japanese Patent No. 2973211) has been known that tilts a sample for cross-section observation, irradiates a focused ion beam thereto, exposes a cross-section of the sample, and then observes (or measures or analyzes) the cross-section by using a scanning ion microscope function of a focused ion beam system.
However, since the cross-section processing with FIB may damage the sample due to the beam, it is difficult to observe a material or structure susceptible to damage, which is a problem. Particularly, a p-n junction of a semiconductor may not appear clearly due to damage by FIB processing or finishing processing with argon ions, which is another problem.
On the other hand, hitherto, a method for preventing damage on a sample has been known that mechanically cleaving a sample to expose a cross-section thereof and acquire a clear cross-section SEM image thereby. However, it is significantly difficult to cleave a minute specific part.